Manufacturing processes that involve materials such as paper, film, foil, fabrics or the like often feed the material into the process from storage on reels, spools, rolls or the like. Reels, spools or rolls need to be changed when they run out of material. In order to keep manufacturing processes using such feed systems operating smoothly, splices are used to connect rolls of material to minimize interruption of continuous manufacturing processes. Eliminating interruptions can be especially important in certain high-speed manufacturing processes such as, for example, printing, converting and packaging processes.
One problem with conventional splices used to join flat sheet-type materials is that the splice construction adds to the thickness of the sheet. Multi-ply materials such as label stock present particular splice problems. Generally speaking, multi-ply materials are spliced utilizing an adhesive support tape to join each ply of the multi-ply material or at least the outer plies. In order to avoid extreme variations in thickness along the length of a sheet, multi-ply materials are often spliced by arranging abutting ends to form a butt joint. If the adhesive support tapes join and bond through the butt joint, the splice itself or even the entire web could break when one ply of the multi-ply pressure sensitive label stock is removed.
Conventional splices for multi-ply materials are often constructed so that a piece of film or tape is placed between the plies to cover the butt joint. This cover tape effectively prevents such bonding of the adhesive support tapes. However, the additional layer of material may reduce the processability of the multi-ply material because of the variation in thickness. For example, printability of multi-ply label stock can be reduced. The variation in thickness may also cause multi-ply label stock to lose its registration with the printer.
Thus, there is still a need for an improved splice structure for joining abutting ends of a multi-ply pressure sensitive label stock. More particularly, there is still a need for a thinner splice structure for joining abutting ends of a multi-ply pressure sensitive label stock. Even more particularly, there is still a need for a two-piece splice structure for joining abutting ends of a multi-ply pressure sensitive label stock.